648 Depth Gage Bases Depth gage base with 25SC38 Stem Collet to fit 3/8" (9.5mm) stem dia. (as per AGD). Split bushings for adapting stem diameter are available but not included. 648 Depth Gage Bases will also accommodate the 644 Dial Depth Gage. 644, 644M Dial Depth Gages 0-3"/0-75MM These gages are for longer ranges, and are accurate and simple to use. Put the contact on the work to be measured and push the gage head down until the base stops at the reference point and take your reading. Furnished with three rounded-end contact points to cover the range. Flat end contact points are also available on special order. The zero setting can be checked with the shortest contact in place by pushing down on a flat surface. Depth Gages 644 Dial Depth Gages In Case Without Case Range Graduation Dial Reading Cat. No. EDP Cat. No. EDP 644JZ 52718 644J 52719 0-3" .001" 0-100 644MJZ 56027 644MJ 56028 0-75mm 0.01mm 0-100 648 Depth Gage Bases Cat. No. EDP Base Size 648-4 65850 4" (100mm) 648-6 65851 6" (150mm) 648-8 65852 8" (200mm) 644J 648-4 131 starrett.com D epth G ages